I've had a few thoughts regarding iruyeh-tan lately that I wanted to share with you

i imagine her to be heyuri-tan's twin sister, they were raised together but heyuri-tan was clearly the favourite child, she tries and tries to get noticed by her family, friends, even strangers! but everyone always only talks about heyuri. So I believe this is why iruyeh-tan is so evil and against fun: it's the only way she has to get the attention she never got as a child
we may see her laughing evilly as she b0rks rule 8 but I believe that when all is said and done and she gets home she cries herself to sleep :(